Total Quality Control: Evolution of Quality Management Systems

Validation of Some Procedures for Quantifying Platinum at sub‐μg/L Level in Some Real Matrices by Catalytic Adsorptive Stripping Voltammetry

“…The average platinum content obtained by the ten repeated analyses was 21.4 and 101.0, respectively. The control rules applied in this chart were the 1 2s and 1 3s [46].…”

Quality Assurance, Quality Control and Method Validation in Chromatographic Applications

“…Eventually, it became clear that for medical laboratories to succeed, they needed to adopt specifications that would ensure the reliability of the qualitative and quantitative results they report. Quality control and assurance benefit the laboratory, because they increase productivity (Westgard and Barry, 1986) and maximize the cost-to-benefit ratio of medical laboratory testing .…”

“…Based on the work of Shewhart, Levey and Jennings, Westgard and co-workers proposed in 1981, an algorithm for monitoring quality control in clinical laboratories (Westgard et al, 1981). 'Westgard's Rules' provide guidance for determining when control values are acceptable or, alternatively, when control measurements reflect changes in the performance of the analytical method (Westgard and Barry, 1986;Burtis and Ashwood, 2001). In a Levey-Jennings control chart, the x-axis represents time or number of analytical runs and the y-axis represents the control results (Figure 1.1a).…”

“…However, if there are other sources of error, then the cusum will deviate from the mean value in one or the other direction. Other quality control charts, such as mean, standard deviation and range charts, are used in industry, but are not common in clinical chemistry and toxicology (Westgard and Barry, 1986). …”

Quality Control Monitoring & Evaluation of Bilirubin, Alkaline Phosphates and Inter-Laboratory Assessment of two Hospitals in North Central Nigeria

“…These rules need to be applied carefully so that true errors are detected while false rejections are minimized. The rules applied to high volume chemistry and hematology instruments should produce low false rejection rates [4,5,6 ].…”